Contact-holder.



A. SUNDH.

CONTACT HOLDER.

APPLICATION FILED 3.25, 1905.

1,083, 11 8, Patented Jan. 1914.

g sums-sum" 1.

WITNESSES" INVENI'OR ATTORNE A. SUN'DH. CONTACT HOLDER.

APPLICATION FILED MAR. 25, 1908'.-

Patented J an. 6,1914.

a SHEET8-SHEET 2.

Q2Ameww and u eful Iinproveiiientfiii Contact-Hold provision of a contact holder which will vei 'im'prov'ed contact holder, with'a contact in and {holders therefor, certain parts being" -vieW of an electromagnetic switch, showing view-of a modification of a portion of Fig.

- UNITED sraras PATEN T orator..-

AUGUST SUNDH, or Yarn inns, New YORK, ASSIGNOR TO OTIS. ELEVATOR-COMPANY,-

o'r JERSEY CITY, NEW JERSEY. A CORPORATION 01' NEW messy.

con'racrrrroLnnn.

a iicmon fiiea mr ii 25';19os., Seriallio. 423,172.

Specification of-iLetters' Patent. i

Patented an. 6,

citizen of. the Viiited States, residing at" Yonkers, in the county of \Vestches'ter and; State of New 1o rk. .ha \'e. invented: a new ers, of which the following is a specification.

. .My inrention relates to electric switches and one itsobjectsis thep'rovision of. simple andefiicient means. for reta ning contacts in Ta. holder-with a tight fit.

' A further obfect'ofthe inventi'o-iiis the feet a wedging of the contact "in theholderwithria tight. fi t--w'hen used-in .aIii eIeCtri switch. f Other obie'cts of the invention will appearhereinafter, the novel combinations of ele ments being -"set .-fortli the appended.

claims,

In the accompanying drawings.- F gure 1- represents aiplan. viewofone form of myplace therein;Fig.'--2 is a side' ele'yatioirof a completelelectt'oinagnetic switch, show ng theap'p'lication of, my in-ve ition; 'Fig; 3 is a" front. elevational view of 'a, modified contact holder, wit'h .a.' contact therein;-- Fig. 4' is a sideview of fixed and movable contacts shownin section Fi'g.-5 is l plan yiebf of a. fragmentary. portion vof Fig. 4: Fig. 6- is a front elevational' viewof another, modified contact holder; Fig. 7 is side multiple switch,

larged fragmentary View of an electric switchcomprising a; plurality. of contact holders; Fig. 9 is a side yiew of still another modification oi" a. contact holder; Fig. L0 is a transverse sectional View of F i'g.-9; Fig. 11 is a'view similarto F ig. 4, and shows the contact holder of. Fig. 9 with the clamp omitted; Fig. 12 is a transverse sectional view of Fig. 11; Fig. 13wis a side elevational the application of the contact holder shown inFigs; 11 and 12; Fig. 14 is a fragmentary Fig. 115 is a front elevational view'of the Contact holder shown in F ig.,14, the Contact itself being omitted; and Fig.'16 is a view similar. to. Fig. .14 s'liowingjthe contact fliltedas 'inzjFig. .11. i '-S m1lar reference characters designate similar partslthroughout the warious views.

Heretoforeit has been the practieetopro-p :Y de contacthol ders comprising sp'ring or nscrew'clamps for holding'the" contact in firm electrical conne tiodwith the electric conductors, .but more or less :trouble has been experienced, for the reason. that the-carbon.

contacts becomef-1oose' in the hol'dersjand thenmakepoor electrical connection, which.

results in overheating of-the carbon and its holder, In some instances the vibration of.

j-the holder and its'contact, duet o the con.-

tlnuous oge ra-tionof theswitch, is sufficient to cause t e contact to drop out ofits place.

It is-among thespecial objectsof in-.

vention, 'not'only'to lessen the dost- 0f -.pro-p du'ctionof cdiitact holders, but also to render them much-'more'eflicient, in that each time that the electric-switch is-operated the contact is wedged 'more tightly in place,

thereby maintaining electrical connection" and the consequential effects.

1' and 2 Ihave shown a contact: holder H 'which comprises the stem- 1, intended to extend through the. cont-roller board Band held in place -'by the nuts '2. 2, between which may be connected a terminal or conductor-.33. f At its-outeror front end the stem 1 is 'provided with a slot'24,-and

through the holder H,transver'sely of said slot, extends a bolt'B. with a nut 17 on its threaded end, as shownin Fig. '1 web =28 fitting in 'a, slot inthe board may be used to' prevent rotationofthe holder. Now, it the'inside faces-.of the'jaws 8, 8 are such that the contact C may be slipped in between them from either. side ofthe holder H, it is evident that if -the holder and the cont-act expandiunequally, orif the nut 17 becomes loose, the contact Cwill make poor electrical connection, and in some instances drop out of itsp1ace.- As shown" by the dotted lines 25 in Fig. 1, I have changed the'shape of thejaws 8, 8 so that the opening at one'side of the contact holder isgreatr than the opening on -the other side of the holder. The contact C is correspondingly shaped, but it will be seen that the contact can be placed intothe holder from only onesjide. Preferbly the wider opening should be a th p in Fig. 2.

be stripped or placed in proper position on side of the holder smaller than on the other so that the holder will appear as indicated.

In Fig. 2 I have shown connected rigidly to the board 13 an altemiating current maguel M, having an armature A which is pivoted at 23 and is limited in its downward movement by the butter stop S. The armature is shown in the position it would occupy when the magnet M is energized. At this time the spring 13 holds the lever L in such position that the contact 3 engages the contact C and current may flow from the conductor 33 through the stem 1, holder II, contacts C, 3, and conductor l t'to the apparatus tobe controlled. Vvlien the magnet M is dencrgized, thcweightof the armature A causes the same to fall and act against the adjustable abutment 11 to more the-lever L on its pivot 1? against the action of the spring 18, and open the switch comprising the contacts'C and 3. It will be seen that each time the magnet is energized and the armature A drawn to its attracted position, the spring 13 causes the contact 3 to strike a blow against the contact C, This blow is directed substantially perpendicularly against the contact 0, but a component of the force is exerted to wedge the contact C more firmly'in its socket, that is, the tendency will be to more the'contact C downwardly from the wider to the narrower por tion of the holder l-I.

By the use of the contact holder shown in Fig. 1, the resiliency of the stem 1, due to the slot 2.4, will maintain the jaws 8, 8 in contact with the carbon'G, through a certain range of difference of expansion of the holder and the carbon, even when the carbon may be placed in the holder from either side. Therefore by making the opening on one side, an additional advantage is obtained. by reason of the wedgiug principle. lVhcu the carbon is clamped in position and the wedging action is taken advantage of, 'itis-' not necessary that the holder H be fastened to the board. B so that the sides of the holder II will be vertical.

In Fig. 3 I have shown a wedge-shaped contact C in a. holder H withoutany means for clamping the jaws of the holder against the contact. I have, howe\-'er, shown a cotter pin R extending through brackets 26, 26 01? the holder H and across the larger space between the jaws, so that after the contact is placed in the holder loosely it will be retained in such position and thecontact holder with the contact therein may the controller board withouttaking care that the contact fits tightly in the holder. Furthermore, itwill be immaterial in whatposition the contact holder is placed on the board, for any blow striking squarely against the contact will immediately result,

switch enga es the in the same being wedged tightly 'in the holder with a firm electrical connection, and such connection is maintained by subsequent operation of the electric switch, for cach time the latter operates the tendency is t ,more tightly wedge the contact in place.

This will be more evident from an explanation of Fig. 4, where it will be seen that. the front 'face 9 of the holder itself is inclined from one side to the other so that the contact C will slide along this inclined face into the narrower p'ortion'of the socketwhenever the contact-C is struck'by the other contact of the switch.

As indicated in Fig. 4, the contact holder II is rovided with a 'stem'l' which is screwthrea ed at the end opposite the holder to receive thenuts 9., 2. The movable contact 4 may be provided with a stem 5 extending throllgh an lnsulating bushing i carried at the outer end of the lever L.- The end of the stem 5 opposite the contact 14' is screwthreaded to receive the nuts 6, 6, one'of which bears against the washer 20 to hold the contact 4 rigidly in place with respect to' thelever L. Between the two nuts may he clamped the terminal of the conductor 14-.

Fig. 5 is a plan View of Fig. 4, the dotted lines showing that the lower'portion of the contact socket is narrower than the upper portion. This will be clear by considering this view in connection with Figs. 3 and l. Fig. 'lby its dotted lines also shows that the lower portion of. the contact socket is narrower than the upper portion and inclined downwardlytoward the back of the body of the holder.

' In Fig. 6 I have shown a holder H" with 'a contact C therein, the space between the jaws lO, 10 being wider than the space between the portions 9, 9. The contact. C is here sliown substantially square. The bottom of the socket, or its face against which the bottom. of the contact C hears. is'alsn inclined toward the back of the body of the holder, so that when the contact C .is struck a blow the tendency will both force the same backwardly and to the left, asviewed in Fig. 6, thus wedging it more tightly in place. This form is-inteuded to illustrate that if the contact C is once lightly fitted in place the holder need not he provided with any means for keeping the carbon from falling out, its position on the board being immaterial, except that when a square contact isused it should be placed in such a position that whcn-theothcr contact of the. g 4 same there will be a maximum area of contact.

Fig; 7 is, a view similar to Fig. 2. but shows the application of the modification .illustratedin Fig. 6. The holder is shown with a plurality-ofwedge-shaped sockets, in this instance three, 'so that the movable contacts are" all electrically connected to- Ill 'g'ether and'to the conductor 14. The fixed "contacts nm'y also be pro ided with, wedgeshaped sockets and may 'be connected to-- gether electrically 'or be electrically independent.-

l ig.- 8 shows a plurality .ofspring-pressed holders. H'--,'e2 1ch. provided with a wedge-v shaped socket and a correspondingly shaped contact (1'. I'n'this instance the upperfend'. of the lever L carries a singleholderwith a plurality of. wedge-shaped sockets for the con'tnctslQ. Figsl 7 and 8 are merely to. show avarious iapplications'to' which the invention maybe'p'ut. Obi'iously theinverts tion may-be used to advantage in many other connections and "-other types of electrieswitches', with alternati-ng'eurrent and direct current. .The'st'em 1", ninybe square] v I in cross-section to preventrotationof the mntnct-ho'lder.

In Figs. 9 and .10 I liave'sliowha cylindriczilly-shaped holder H' provided with lateral openings 21. --This holder is cup shaped, and the bottom thereof OlLthe-irr side" at 16 isof. less'diameterthan the outer portionv thereof at .15., so that; a. e0nt :1et' snugly fitting-in thi'sicup .willhave' the shapeof a frustumiof. a'eone. The holder may. have a slot as indicated at" 22'- in: Fig. 10, end also wing-s or projectionslti, 18 for- ;receiving a bolt1R,so; that after the;contact and 12. a

is placed. in position it;- maybe clamped tightly to theiholder. b'y'turning the'nut 17' Now, it is; evident thatwhen this cup-shaped contactlmlder and the frusto-coniealf. con-1 tact therein is embodied-"in the switch shown in Fi 13',"s uch contactwillbe'wedged more inplace each time thesIwitch-is per tight mitte to be closed.

'- In ,order" to. insure non-slipping, of the;

contact fromitsholder, I ll-ave shown the inner portion of the contact fluted'spirally.

as indicated at 27 tofit'. corresponding fproject-ionspn the inner walls of the holder, as indicated-in ,Figs 10 and 12. It will be seen that with this arrangement the tendency will be for the contact to rotate in its socket :when ,it. is wedged more tightly in place, and by reason of the greater surface.-

and the spiralfluting a greater frictional re-. sistance .is obtained. This friction may be sufiicien't to permit the =0missio'n of the. clamp comprising the .wings 18, 18, thebolt' will-also. be see'nR'thatf the metal sleeve -28 slides. through the opening .'n the lever-L so that the. insulating bu'shings-not subjectedfto wear, It' shoultl be o ryed, however, that when spring-pressed contacts-are used the insulating 'bush-ing is not =so-imp0rtant when .the "wedge-shaped socket holder is used,-for .in' the latter event the heating at the switch con'talzts is reduced to a minimiim.;

In .Fig. 14; -I have. shown'a cup-shaped holder i H"-. provided {with lateral open} 15' is larger indiameter than the bottom at 16 andjisinclined-with respect .to the axis of the stem. I;' Th' contact is 'corre}; spondingly .,Shi1Ded. lVith -,this fllfl a lgg-i -ment the contact will. be forced-into the narrower"; portion ,(if the holder .an"d.- also to one sideflthereofi with a wedgin'g action, by

- reason-of the narrower space at-the'bo'ttom and the inclination with respect to thelaxis. of theistem '1'. Fig; flo'sho'ws'. a front 'vi'ew off the-holder withthe contact omitted.- If desired, the cross sectiona l area. of the con .tact and the socket maybe "irregular as; -shown in Figs;" 9-, 1:0 and; -11 so. that rotation of the eontact'wi'l-l beprevented. g

16 ism-many respects similar to Fig.

14', butshoiving the"conta.ct. C"" fluted at' '27 similar to the fluted contacts 'C. of igs:

From the'. foregoing :deseription'it' will .Seen'that I-"have provideda .very simple 1 contact holder with inner 'wedging-su -faces1 Thecbntact may be'clam'ped in the'holder as shown. in Figs."1,.9 and 10, or itrnay be' socket'between the converging jaws by m'eans of, '9, cotter -p'in,,as indicated in Figs. 3, and 5].: ."In some'instancesthe holder v mayv be cup-shape d; 'as shown. in

provided fOlf thje'in'sei tione fan imp ement' .to pry out th e contactwhen it is desiredto remove the. same.- suchfg opening also. perv mits the 1nsertion'.,of the; contact with faw cility,as no air 'is thenrc'onfined andput' under pressure tending to release the cons tact, It should be notedthat in Figs; -1 to 8, inclusivgand i -Figs, 14 and 15 the inner wedging" surfaces fare inclined rearwardly,

that '-is,' inclined toward the back of -the'l' holderwith respecttothe axis of the stem or the plane of. the" face of the 'c0ntact.

During 'thje operation of switch mechanism embodying'any form of'my'in ntion-the' cont'act isiwedged'more t1 ht 1 9 whenever struck squarel'yon t ietaee"; nevertheless, the contact may be easily removed by loosening the clamp. if any, or by simply striking the block units narrower exposed side, or by prying it out if the cup holder is employed.

I-wish it to be understoodthat I do not desire to'be limited to theexact details of construction shown and described, for ohi'ious modifications will occur to a person skilled in the art.

Having thus fully described my invention, what- I claim and desire, to have prot-erted by lietters latent of the United St ates is a i. In an electric switch, the combination with a cup-shaped socket irregular in crosssection and tapering toward its bottom, of a frusto-conical contact in said socket, and means for clamping the socket on the contact. o 7 a In an electric switch, the. combination of a contact, and a cup-shaped socket for receiving and holding said contact, said socket having a lateral opening for the insertion of an implementto remove the contact.

In an electric switch, the combination of a substantially spirally fluted contact block, and a correspondingly shaped holder therefor.

. .4. In an electric switch, the combination of contact having a fiat face and an extension fru'sto-conical and inclined with respect to said face, the smaller end of said extension beingremote from said face; and a of fluted and slightly convergent, thesaid contact block being fitted in said socket and having lateral faces correspondingly convorn'ent, whereby the impact otthe contact block against the said stationary contact when the switch is operated will tend to drive the Contact block more tightly into its socket.

6. In an electrical switch, the combination of a frusto-conical contactbloclcand a' '8. The: combination of an electrical contact holder provided with a stem and formed with a frusto-conical'socket the axis of said socket being inclined to the said stem, and a contact block fitting in said socket.

In testimony whereof, I have signed my:

name to thisspeci'tication in the presence of two subscribing witnesses.

AUGUST SUNDH.

Witnesses:

WM. Dna'rs, E. F. CnY'rnu's. 

